Respiratory Pigments
Cooperativity
1st molecule of O2 is not bound readily, but after first, it changes shape so others bind more readily, increased affinity
Hemocyanin
2nd most common, mollusks and anthropods. Colorless when not bound to oxygen, bright blue when oxygenated
4 types of respiratory pigments
Hemoglobin, hemocyanin, hemerythrin, and chlorocruorin
Respiratory pigments
binds to oxygen and consists of a protein molecule and an associated metal ion
increases rate of reaction
carbonic anhydrase
Iron
center of each heme sub unit
Hemerythrin
marine invertebrate phyla. Oxygenated=pink deoxygenated= colorless
Hb A
most common, 2 alpha subunits and 2 beta subunits held together noncovalently. each subunit reversibly binds to a single O2 molecule
hemoglobin
most common, many invertebrates and all vertebrates. the unit is a globin protein that has an associated heme group. The iron atom= red oxygenated blood and blue deoxygenated. vertebrates= in RBC, invertebrates= blood cells or free in plasma
Chlorocruorine
only in marine animals. Dilute form= green. Concentrated form=red
Myoglobin
stores oxygen in muscle tissue
Bohr effect
the ability of hemoglobin to bind oxygen decreases with decreasing pH